1. Field of the Invention
The present invention relates to a device and an installation for the instantaneous and multipurpose detection, inside and/or outside, of physical phenomena having a character of risk and being as varied as intrusion and/or fire and/or explosion and/or leaks (of fluids and/or "electric" ones) and/or else the disturbance or absence of a movement or of a regular or periodic phenomenon, taken separately or together and possibly simultaneously.
2. Description of the Prior Art
In the particular case of fire detection, different types of detectors are used at the present time which are able to measure the presence of one or other of the following physical phenomena:
combustion aerosols,
combustion gases,
visible smoke,
flames,
temperature threshold,
rapid temperature rise.
From the point of view of the physical phenomenon detected, fire detectors are distinguished as indicated below:
ionic detectors, which allow combustion aerosols to be detected and which are responsive to the variations of the properties of an artificially ionized atmosphere;
optical smoke detectors, responsive to the presence of visible smoke, which are of the so called:
opacity type (responsive to the attenuation of light due to the presence of smoke), and
diffusion type (using the diffusion effect of the light due to the smoke);
optical flame detectors, which use the energy radiated by the flames (for reasons of stability and selectivity, the visible radiation of the flame is not used but rather the infrared or ultraviolet radiation);
heat detectors, whose sensitive element measures:
a preset temperature threshold (temperature threshold detector), or
the rate at which the temperature rises (thermovelocimetric detectors).
In addition, so called special detectors are known, more particularly:
ember detectors, which are specifically used for detecting the unmodulated infrared radiation characteristic of ember fires;
acoustic detectors, which measure the bursting noise of a bulbcontaining a gas which, under the effect of the pressure increase due to the heat, causes the bulb to "burst";
laser detectors, which provide a linear check of the variation present, on reception, in a coherent photon beam emitted by an appropriate source and caused by the convection movement due to the seats of the fire, and
surface effect detectors, which in their basic principle are used as dangerous gas detectors.
In so far as fire detection is concerned using said means, they have a certain number of drawbacks, more particularly:
in so far as ionic detectors are concerned, they are slow and are never used outside because they are influenced by air currents; furthermore, they may cause untimely alarms (i.e. without real danger) too frequently;
in so far as optical smoke detectors are concerned:
the operation of opacity type detectors is greatly disturbed in dusty atmospheres and they react with a certain delay for smoke emissions of low opacity, whereas
diffusion type detectors have difficulty in detecting black smoke because of their poor reflecting power;
furthermore, diffusion type detectors are too slow and are never used outside;
in so far as flame detectors are concerned (infrared or ultraviolet detectors), although they may be used outside and although they are rapid, the corresponding detection area (or surveyed area) is very much reduced; in addition, they are sensitive to atmospheric phenomena (more especially to the illumination due to lightning and the sun) and the object being monitored must be fixed: in addition, outside protection requires a certain number of requirements to be complied with which make it complicated and expensive;
in so far as heat detectors are concerned, they are slow and are never used outside;
in so far as the so called special detectors are concerned,
ember detectors, which may be used possibly outside as well, are at present still in the experimental application stage,
acoustic detectors, when they are used outside, are disturbed by the surrounding noise,
laser detectors provide detection along an axis and not of a volume, so that their outside use, more particularly, requires a large number of this type of device to be used (which are at present economically valid essentially for protecting large inside areas, for example supermarkets, and
surface effect detectors, which have solved the problem of the monitoring range, have a sensitive element subject to chemical drifting and, furthermore, they are expensive.
In short, and generally, still limited to the particular case of fire detection, the traditional systems rely on the analysis of physical phenomena (more particularly optical, thermal, mechanical phenomena) and chemical phenomena using detectors which are very specialized in their functions and whose design compels use thereof almost exclusively inside, in that no detector lends itself to outside use without enormous constraints which greatly limit the real use of some of them to rare specific cases and which completely prohibit the other applications.
Furthermore, to the knowledge of the applicant, there exists at present no single system which is capable of detecting outside as well as inside, not only the different manifestations of a fire, but at the same time other physical phenomena as well having a character of risk , such as intrusion, and/or leaks (of fluids and "electric" ones) and/or explosion, for example, as well as a priori any character of disturbance or absence in the regular movement of a system which may have dangerous or, in any case, undesirable consequences for the correct operation of the system.